1. Field of Invention
This document describes a technology for painting and image printing that utilizes a simple system with multiple colorants and a single printing head through which the image is printed by a transparent ink or binder. The primary area of interest involves dry pigments of larger molecular weight colorants, such as cholesteric liquid crystal (CLC) pigments, and their diverse applications in modern printing and painting. In addition, new techniques can be easily expanded to serve more functions, such as 3-D stereoscopic image capability.
2. Brief Description of the Literature
Broadband reflecting polarizers were introduced in application Ser. No. 08/550,022 (now U.S. Pat. No. 5,691,789) entitled xe2x80x9cSingle Layer Reflective Super Broadband Circular Polarizer and Method of Fabrication Thereforxe2x80x9d by Sadeg M. Faris and Le Li which was filed Oct. 30, 1995. Such broadband polarizers are made by producing a single layer having cholesteric liquid crystal order where the pitch of the liquid crystal order varies in a non linear fashion across the layer.
General references on polymer dispersed liquid crystals may be found in detail in xe2x80x9cPolymer Dispersed Liquid crystal displaysxe2x80x9d, by J. W. Doane, a chapter in xe2x80x9cLiquid Crystalsxe2x80x9d, Ed. B. Bahadur, World Scientific Publishing, Singapore, and xe2x80x9cCLC/polymer dispersion for haze-free light shutters, by D. Yang et al. Appl. Phys. Lett. 60, 3102 (1992).
Since the early attempt of utilizing cholesteric film as optical filters and the effort on polymer encapsulated nematic liquid crystals for display, much attention has been focused on trying to bring polymeric liquid crystals and cholesteric liquid crystals together to make devices for light control application. (See, for example J. Adams, W. Hass, J. Dailey, Journal of Applied Physics, 1971, and J. L. Fergason, Society for Information Display Digest, 1985.). The above identified US patents and other references are hereby incorporated by reference.
3. Related Cases
The following applications are related to the present invention: application Ser. No. 09/093,017 filed Jun. 5, 1998; application Ser. No. 09/093,006 filed Jun. 5, 1998; application Ser. No. 09/039,303 filed Mar. 14, 1998; application Ser. No. 09/039,297 (now U.S. Pat. No. 6,072,549) to Faris et al., entitled xe2x80x9cIntelligent Glazing Structures with Additional Control Layersxe2x80x9d filed Mar. 14, 1998; application Ser. No. 08/891,877 filed Jul. 9, 1997 entitled xe2x80x9cReflective Film Material Having Symmetrical Reflection Characteristics and Method and Apparatus for Making the Samexe2x80x9d, by Le Li and Sadeg Faris; application Ser. No. 08/890,320 filed Jul. 9, 1997 entitled xe2x80x9cColoring Media Having Improved Brightness and Color Characteristicsxe2x80x9d by Sadeg Faris and Le Li; application Ser. No. 08/805,603 (now U.S. Pat. No. 5,940,150) entitled xe2x80x9cElectro-optical Glazing Structures having Total-reflection and Transparent Modes of Operation for use in Dynamical Control of Electromagnetic Radiationxe2x80x9d to Sadeg Faris and Le Li, filed Feb. 26, 1997, which is a continuation-in-part of: co-pending application Ser. No. 08/739,467 (now U.S. Pat. No. 6,034,753) entitled xe2x80x9cCircularly Polarizing Reflective Material Having Super Broad-Band Reflecting and Transmission Characteristics and Method of Fabricating and Using Same in Diverse Applicationsxe2x80x9d to Le Li, Yingqiu Jiang, and Sadeg Faris, filed Oct. 29, 1996, which is a continuation-in-part of co-pending application Ser. No. 08/550,022 (now U.S. Pat. No. 5,691,789) entitled xe2x80x9cSingle Layer Reflective Super Broadband Circular Polarizer and Method of Fabrication Thereforxe2x80x9d to Sadeg Faris and Le Li, filed Oct. 30, 1995; co-pending application Ser. No. 08/787,282 entitled xe2x80x9cCholesteric Liquid Crystal Inksxe2x80x9d by Sadeg Faris, filed Jan. 24, 1997, which is a continuation of application Ser. No. 08/265,949 (now U.S. Pat. No. 5,599,412) entitled xe2x80x9cMethod and Apparatus of Producing Aligned Cholesteric Liquid Crystal Inksxe2x80x9d to Sadeg Faris, filed Jun. 27, 1994, which a Divisional of application Ser. No. 07/798,881 (now U.S. Pat. No. 5,364,557) entitled xe2x80x9cCholesteric Liquid Crystal Inksxe2x80x9d to Sadeg Faris, filed Nov. 27, 1991; co-pending application Ser. No. 08/715,314 (now U.S. Pat. No. 6,188,460) entitled xe2x80x9cImage Display Panel having a Backlighting Structure and a Single-layer Pixilated Array of Reflective-type Spectral Filtering Elements where between Light is Recycled for Producing Color Images with Enhanced Brightnessxe2x80x9d to Sadeg Faris, filed Sep. 16, 1996; co-pending application Ser. No 08/743,293 (now U.S. Pat. No. 6,133,980) entitled xe2x80x9cLiquid Crystal Film Structures with Phase-retardation Surfaces Formed Therein and Methods of Fabricating the Samexe2x80x9d to Sadeg Faris, filed Nov. 4, 1996. Each of the above identified U.S. Patents and U.S. Patent Applications are commonly assigned to the assignee of the present invention and are fully incorporated herein by reference.
In modern society, information exchange plays an important role. Efficient methods to convey information rely on high-quality communication devices. Among them, printing and painting devices are becoming more and more important. Currently, ink-jet, bubble jet, and laser printing, along with off-set, flexo press, and screen printing are universally used. All of these printing techniques possess a common feature. In order to perform color printing, multiple nozzles or screens must be used for cyan, magenta, yellow and black colorants. This forces the printing system to become mechanically complex and limits the system from being able to be expanded to serve multiple functions such as the case of 3-D printing. In addition, since the printing nozzles and screens have a very fine apertures, they can""t handle those colorants with relatively larger pigment particles.
Furthermore, it has been known that CLC can be used as a colorant for painting and printing because of their excellent spectral characteristics and wide color range properties. However, special techniques must be employed in order to use CLC. Special surface treatments and curing methods are all necessary to print and dry CLC films. As a result, CLC has never been practically used in real artwork or other applications. However, the present invention of the new CLC ink based on CLC pigment solves all these problems at once. No special surface treatment and curing equipment is required to dry and/or cure the colorant. Another benefit is the capability of generating colorful 3-D stereoscopic images since the CLC ink reflects polarized light.
One objective of this invention is to improve today""s printing technologies. The inventors of the present invention have developed a new printing technology that offers a simple system configuration, greater flexibility, improved printing quality, and enhanced functionality. The new technique is termed Dry Printing Technology (DPT) by its working principle. It uses only one printing head and prints images with an invisible ink. It can handle, in principle, all kinds of colorants, even colorants with larger pigments so that it removes the pigment size constraint in ink jet nozzle printing. By adopting a new printing head combined with CLC pigments, dry printing offers enhanced image quality. Finally, DPT can be easily expanded to print a colorful picture in 3-D with the CLC pigments.
Another objective is the application of the invented printing technique using a newly developed, novel colorant to achieve unique display effects that usual technologies do not possess. The ink is made from CLC pigments mixed into a suitable optically clear carrier.
Yet another objective is to give printing devices more flexibility and enhance their functionality.
Yet another objective is to achieve a special visual effect of objects which appear to have different colors depending on the viewing angle.
Yet another objective is to create 3-D stereoscopic images in full color at any size.
Yet another objective is to provide security printing.
Yet another objective is to provide unique cosmetic effects.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considering in conjunction with the accompanying drawings.
The present invention applies a dry pigment to a surface which has been prepared with a binder layer for binding the pigment. The binder layer is either prepared in a pattern, so that the dry pigment sticks to the pattern only, and then the pigment layer and binder are cured or fixed, or the dry pigment is applied in a pattern to a uniformly coated binder layer, and then the binder layer is cured or fixed to fix the dry pigment. Flakes of iridescent pigment material are aligned parallel to each other to provide iridescent coatings.